So back to my question above.
Is the only difference between the MK I and the MKIII the piston & spring? If so why can't AA (or somebody) make a conversion kit for the MKIII? With so much interest it seems like they would sell them. This is essentially something they have already made so the development time should be short. Just program the CNC machines and crank out a few thousand units and see if they sell. If not put them in rifles and sell special "short stroke" TX200 MKIII and add $200 to the price.